Quote:
Originally Posted by LJohnson32
I agree -- seeing the viscosity under the specified range has been something I've been keeping an eye on for sure. I suppose I've been comfortable with it based on the summary/feedback given by Blackstone that it seems to be harmless. As far as thermal management, once the oil temp needle registers above the 160 dash, I always switch into my M1 program which includes Sport Plus drivetrain to run the water pump full time. Average operating temp usually tops out at ~200F as opposed to ~230F without Sport Plus. Curious to hear what temps you're seeing in Sport Plus under normal driving conditions at the higher weight oil.
My driving behavior rarely (if ever) involves sustained high load, so the fact that I'm not seeing elevated levels of copper and lead (bearing material) suggests that the oil is appropriate at least for my driving style. If I were running a tune as you are and putting higher sustained loads on the engine, the 5W-50 would be an obvious choice I think.
I'm definitely still thinking about the 5W-50 after seeing the way your reports are trending -- I guess being stock and having a generally conservative driving style has kept me satisfied at the 5W-40. Not that it's anything to place a lot of weight on (no pun intended), but remembering that the factory oil weight is a 5W-30 also makes me less worried if the LM 5W-40 shears down to a 30 weight at temp, along with Blackstone's comments about the shear being harmless.
Nonetheless, you still have me questioning if I should be switching. The 5W-50 seems to be doing great at handling the higher loads with your tune, so it's safe to assume it would probably do just as well if not better on a stock car with a generally conservative driving style ~80% of the time.
|
My coolant temps in sport plus trend near between 180-190F once fully warmed up and my oil stays between 200-220F. this is also with an ambient temperature between 70-90F in the Northeast summer, but overall has been consistent. I can check live data from my awron vent gauge so its interesting to see the temps before, during and after some spirited driving.
I notice my 5w-50 will stay hotter, longer, as the oil i think retains the heat more, or maybe its best to say its good at taking the heat out of the metal, but not at relinquishing it.
Its very good to keep the car in sport plus to help pull the heat out of the coolant, i have seen my coolant stay above 230F while in comfort, driving casually. keeping the car in sport plus i feel is better for the longevity of the engine.
As for your case you may be correct in thinking that if it shears closer to a 30 weight you may be fine, but regardless of tune, the engines run pretty hot especially when driving around casually. if you ever want to try the 50 weight you could i dont think it will harm anything, but i think the extra peace of mind from the shear strength and the higher moly count is great for long lasting protection.
I will continue to gather samples of my car on the redline and most likely do another sample in 3000 miles, i wanted to see how the oil performed at the 4500 mile range and it seems to be fine, but i would rather change at 3000, when i changed the oil it was considerably darker in my opinion then when i changed it at 4500 miles when i changed it at 3000.
Only time and more data will tell